Students at Dyker Heights Intermediate School in Brooklyn were relocated Tuesday after a window fell into a classroom the day before.
Sources say there were children inside the classroom at the time, but no one was hurt.
There is construction going on at the school, but it's not clear if the work is connected to the window collapse.
The Department of Buildings is now investigating.
Students were sent to nearby McKinley Intermediate School 259, Christa McAuliffe Intermediate School 187, and New Utrecht High School.